A coffee bean is a seed from the Coffea plant and the source for coffee. It is the pip inside the red or purple fruit. This fruit is often referred to as a coffee cherry, and like the cherry, it is a fruit with a pip. Even though the coffee beans are not technically beans, they are referred to as such because of their resemblance to true beans. The fruits most commonly contain two stones with their flat sides together. A small percentage of cherries contain a single seed, instead of the usual two, called a "peaberry". The peaberry occurs only between 10% and 15% of the time, and it is a fairly common belief that they have more flavour than normal coffee beans. Like Brazil nuts and white rice, coffee beans consist mostly of endosperm.